I have Ubuntu installed back when 14.04 was new and fresh. Not it has gone through several updates and now it's at 16.04.
My laptop has 8GB of DDR3 memory @ 1600MHz with i3 processor. So it's not most powerful of machines but it's far from poor.
Recently I have noticed that Ubuntu takes up to 2.8GB of RAM when it just boots up. When I start up Chrome and PHPStorm or some other environment it goes up to 7.8, 7.9GB and just stals. If I use any of Google services written in Angular, Chrome goes to about 2.5-3GB.
At same time, I tried booting up Mint 17.1 on same machine from external hard drive, and it only takes up to 600MB of RAM on boot. So I tried installing Cinnamon but it only got me as far as 2.5GB on boot up instead of "regular" 2.8GB.
As for startup applications I only have Skype Alpha and nothing else. There was Cairo Dock before, but now with Cinnamon it's disabled. I've removed Comodo Antivirus and almost nothing is running. Still RAM gets eaten up very quickly.
Even if I go to System monitor and add up all RAM usage from processes listed there, it doesn't even closely add up to what is actually being taken.
Any ideas why? I'm in the middle of few projects and currently installing system from scratch would be quite a disaster for me